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What is __gxx_personality_v0 for?
... quick grep of the libstd++ code base revealed the following two usages of __gx_personality_v0:
In libsupc++/unwind-cxx.h
// GNU C++ personality routine, Version 0.
extern "C" _Unwind_Reason_Code __gxx_personality_v0
(int, _Unwind_Action, _Unwind_Exceptio...
Determine if string is in list in JavaScript
...
You can call indexOf:
if (['a', 'b', 'c'].indexOf(str) >= 0) {
//do something
}
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Multiple columns index when using the declarative ORM extension of sqlalchemy
...e just Column objects, index=True flag works normally:
class A(Base):
__tablename__ = 'table_A'
id = Column(Integer, primary_key=True)
a = Column(String(32), index=True)
b = Column(String(32), index=True)
if you'd like a composite index, again Table is present here as usual you ju...
Python concatenate text files
...new file. I could open each file by f = open(...) , read line by line by calling f.readline() , and write each line into that new file. It doesn't seem very "elegant" to me, especially the part where I have to read//write line by line.
...
What's wrong with nullable columns in composite primary keys?
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Primary keys are for uniquely identifying rows. This is done by comparing all parts of a key to the input.
Per definition, NULL cannot be part of a successful comparison. Even a comparison to itself (NULL = NULL) will fail. This means a key containing NULL would not work.
Additonally, NULL is al...
Apply multiple functions to multiple groupby columns
...ion.
I recommend making a single custom function that returns a Series of all the aggregations. Use the Series index as labels for the new columns:
def f(x):
d = {}
d['a_sum'] = x['a'].sum()
d['a_max'] = x['a'].max()
d['b_mean'] = x['b'].mean()
d['c_d_prodsum'] = (x['c'] * x['d...
MDI CDockablePane使用总结 - C/C++ - 清泛网 - 专注C/C++及内核技术
...架类的头文件中定义一个CDockablePane的数组
CDockablePane m_Panes[5];//一个CDockablePane的数组
2. CFrameWndEx:: OnCreate() 在Create函数中自动生成了以下代码，对MFC比较熟悉的这里就不讲了：
CMFCPopupMenu::SetForceMenuFocus(FALSE);
InitUserToolbars(N...
Call a “local” function within module.exports from another function in module.exports?
How do you call a function from within another function in a module.exports declaration?
8 Answers
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Creating Threads in python
...see how:
from threading import Thread
from time import sleep
def threaded_function(arg):
for i in range(arg):
print("running")
sleep(1)
if __name__ == "__main__":
thread = Thread(target = threaded_function, args = (10, ))
thread.start()
thread.join()
print("th...
Real world use cases of bitwise operators [closed]
...checksums, parity, stop bits, flow control algorithms, and so on, which usually depend on the logic values of individual bytes as opposed to numeric values, since the medium may only be capable of transmitting one bit at a time.
Compression, Encryption
Both of these are heavily dependent on bitwise ...